Should we invest in HIV prevention for people who inject drugs?

People who inject drugs make up less than 1 percent of the U.S. adult population. But about 10 percent of new HIV infections in this country are attributable to injection drug use.

So it stands to reason that focusing on HIV interventions for injection drug users could have tremendous public health benefits, Stanford researchers contend in a study published this week in the Annals of Internal Medicine.

Cora Bernard, a Stanford graduate student in management science and engineering and lead author of the paper, explains:

We already know that the health benefits of interventions for high-risk individuals extend to the entire U.S. population... And with the recent surges in opiate drug use in the U.S. and HIV outbreaks in places like Scott County, Indiana, it’s increasingly important to invest in prevention programs that are both effective and cost-effective.

The authors used new clinical data to determine that pre-exposure HIV prophylaxis, combined with frequent screening and prompt treatment for those who do become infected, could reduce the HIV burden among those who inject drugs.

And that could provide a public health benefit for all Americans. “Value is an important consideration in health policy decisions that have substantial budget implications,” said Jeremy Goldhaber-Fiebert, PhD, an associate professor of medicine and senior author of the paper.

However, prescription drug costs in the United States are among the highest in the world, making this form of intervention quite expensive. Currently, the U.S. Food and Drug Administration has approved a daily combination of 300 mg of tenofovir disoproxil fumarate and 200 mg of emtricitabine for HIV-negative patients, at a cost of about $10,000 per patient a year.

Add to that the cost of the HIV screening and assessment for adverse effects every three months and monitoring for toxicities every six months. Here's Bernard:

This kind of cost scales fast. Although you’d be preventing the downstream costs of some infections, providing pre-exposure prophylaxis to 25 percent of HIV-negative people who inject drugs for just one year would require an upfront investment of over $3 billion.

Many trials have shown that daily oral pre-exposure prophylaxis — or taking HIV medications to reduce the chance of infection — can prevent transmission of HIV. This prompted the Centers for Disease Control and Prevention to revise its clinical practice guidelines in 2014 to recommend this treatment be considered for any adult who injected drugs within the previous six months, shared needles, enrolled in drug dependence treatment, or was at increased risk for sexual transmission.

Achieving these benefits, however, costs $253,000 per quality-adjusted life year (known as QALY, a common metric used to compare cost-effectiveness interventions.) In comparison, needle-syringe exchange programs cost $4,500 to $34,000 per quality-adjusted life year.

The authors concluded that frequent screening and pre-exposure prophylaxis, as well as prompt treatment for those who become infected, could reduce the HIV burden among people who inject drugs and provide substantial public health benefits. They also found that enrolling 25 percent of HIV-negative people who inject drugs in a program that combined pre-exposure prophylaxis, screening and antiretroviral drugs would reduce the HIV burden in the United States.

But it is expensive.

“Cost effectiveness is only one of many considerations for policymakers, who must also evaluate the ethical dimensions of an HIV prevention program for a population with generally low access to health services,” the authors wrote.

In an editorial that accompanies the paper, Rochelle Walensky, MD, a professor of medicine at Harvard Medical School, asks: “What good is preventing HIV if we do not first save that life at HIV risk?”

The scenario many of us learned in school is that two X chromosomes make someone female, and an X and a Y chromosome make someone male. These are simplistic ways of thinking about what is scientifically very complex.